fú​lì​tiáo​zhěng​zhuāng​zhì

buoyancy compensator

  1. buoyancy
    the upward force exerted by a fluid (liquid or gas) that opposes the weight of an immersed object
  2. to adjust; adjustment
    to adjust, regulate, or restructure (e.g. a system, price, or organization) to suit new conditions
  3. device
    installation; unit; device; equipment; a system or mechanism with a specific function